63 research outputs found

    Data Support in the Choice of Mine Water Treatment Technology

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    Mathematical modeling is used in this work in the analysis of options for the implementation of acid mine water treatment technology. Ta technological scheme of metal-bearing mine water treatment is proposed and includes two stages. The first stage, the treatment of mine water to the required degree to extract solid insoluble sediment for further processing, is implemented in a mobile technological complex installed in places of mine water outpouring. Selective extraction of individual metal powders is delivered in a stationary complex in applying the centrifugal conversion method using plasmatron. In the first step, the metal ions contained in the mine water should be complete recovered with maximum energy-saving. The condition for complete extraction of useful components from mine waters is pH values corresponding to the beginning of precipitation of hydroxides of various metals and complete precipitation, which depend on the nature of metals, their concentration in solution, temperature, impurity content. The process regime must be manageable to ensure its adequacy in the quality of raw materials under conditions of changing mine water flow rates and concentrations of ingredients. The technological mode must be manageable to ensure its adequacy in the raw material quality under changing mine water discharges and concentrations of ingredients. Keywords: technological complex, mine water, treatment, modelin

    Particle flows in a dc discharge in laboratory and microgravity conditions

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    We describe a series of experiments on dust particles flows in a positive column of a horizontal dc discharge operating in laboratory and microgravity conditions. The main observation is that the particle flow velocities in laboratory experiments are systematically higher than in microgravity experiments, for otherwise identical discharge conditions. The paper provides an explanation for this interesting and unexpected observation. The explanation is based on a physical model, which properly takes into account main plasma-particle interaction mechanisms relevant to the described experimental study. Comparison of experimentally measured particle velocities and those calculated using the proposed model demonstrates reasonable agreement, both in laboratory and microgravity conditions, in the entire range of discharge parameters investigated.Comment: 9 pages, 7 figure

    Shear flow in a three-dimensional complex plasma in microgravity conditions

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    Shear flow in a three-dimensional complex plasma was experimentally studied in microgravity conditions using Plasmakristall-4 (PK-4) instrument on board the International Space Station (ISS). The shear flow was created in an extended suspension of microparticles by applying the radiation pressure force of the manipulation-laser beam. Individual particle trajectories in the flow were analyzed and from these, using the Navier-Stokes equation, an upper estimate of the complex plasma's kinematic viscosity was calculated in the range of 0.20.2--6.7 mm2/s6.7~{\rm mm^2/s}. This estimate is much lower than previously reported in ground-based experiments with 3D complex plasmas. Possible reasons of this difference are discussed.Comment: 5 pages, 4 figure

    BUILDING A TOMOGRAPHIC VELOCITY MODEL FOR SAMOYLOV ISLAND AREA (LENA DELTA) FROM LOCAL SEISMOLOGICAL DATA FOR THE PERIOD OF 2019–2021

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    In our paper we present the results of seismotomographic inversion for the local seismological monitoring data obtained in the area of the Samoylov Island (Lena River delta) in 2019–2021. Tomographic velocity model was used for refining hypocenter locations of local earthquakes and for geological interpretation. The results are shown as maps of anomalies of seismic waves and Vp /Vs ratios for the 5 and 10 km depths. The velocity anomalies structure made it possible to interpret low Vp /Vs ratio as rocks related to the Siberian platform, and to compare between the boundary of the low Vp /Vs area and the trace of the known geological fault running along the Olenekskaya Channel

    ПОСТРОЕНИЕ СЕЙСМОТОМОГРАФИЧЕСКОЙ МОДЕЛИ РАЙОНА НАУЧНО-ИССЛЕДОВАТЕЛЬСКОЙ СТАНЦИИ «ОСТРОВ САМОЙЛОВСКИЙ» ПО ДАННЫМ ЛОКАЛЬНОГО СЕЙСМОЛОГИЧЕСКОГО МОНИТОРИНГА ЗА 2019–2021 гг.

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    In our paper we present the results of seismotomographic inversion for the local seismological monitoring data obtained in the area of the Samoylov Island (Lena River delta) in 2019–2021. Tomographic velocity model was used for refining hypocenter locations of local earthquakes and for geological interpretation. The results are shown as maps of anomalies of seismic waves and Vp /Vs ratios for the 5 and 10 km depths. The velocity anomalies structure made it possible to interpret low Vp /Vs ratio as rocks related to the Siberian platform, and to compare between the boundary of the low Vp /Vs area and the trace of the known geological fault running along the Olenekskaya Channel. В работе приведены результаты сейсмотомографической инверсии по данным локального сейсмологического мониторинга, полученным в районе научно-исследовательской станции «Остров Самойловский» (дельта р. Лены) в 2019–2021 гг. Полученная сейсмотомографическая модель была использована для уточнения гипоцентров локальных землетрясений и геологической интерпретации. Результаты приведены в виде скоростных аномалий P- и S-волн, а также их соотношения Vp /Vs , для глубин 5 и 10 км. Анализ структуры скоростных аномалий позволил интерпретировать зону пониженного соотношения Vp /Vs как слой пород, относящийся к Сибирской платформе, а также сопоставить границу области пониженного Vp /Vs с известным геологическим разломом, проходящим вдоль Оленёкской протоки.

    Generalized Reduction in Rings of Differential Polynomials

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    —In this paper, concepts of algebraic reduction and pseudoreduction in rings of differential polynomials are generalized. Specific features of this generalization, such as the uniqueness of separants and termination of the generalized reduction process, are considered. A method for the construction of generalized almost triangular simplificators similar to that for the construction of medians by Gröbner bases is suggested. A particular case, the generalized reduction in an ordinary polynomial ring, is considered 1
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